Brentford are demanding at least £40million to sell Yoane Wissa to Newcastle, talkSPORT understands.The Magpies face the prospect of losing their star man Alexander Isak this summer as it’s understood the striker wants to leave the club.Newcastle have been told how much it will cost to sign WissaGettyIsak has informed them that he wants to explore his options, but the 25-year-old has stopped short of an official transfer request as of yet.Liverpool, who signed former Newcastle target Hugo Ekitike for £79m from Eintracht Frankfurt, have shown interest in the Swede.Newcastle now look set to ramp up their search for a new striker, with Brentford star Wissa a summer target.They have already seen a £25m offer for the DR Congo star rejected and were readying a second bid of around £30m.However, Brentford feel they can afford to drive a hard bargain after selling Bryan Mbeumo for £65m plus add-ons to Manchester United.Should Wissa be unattainable, Newcastle are also interested in RB Leipzig striker Lois Openda.The Belgian has scored 41 goals and assisted 18 others in his last two seasons, and been previously linked with Bayern Munich.Newcastle have already added to their attacking stocks this window via the impressive signing of Anthony Elanga in a £55m deal from Nottingham Forest.However, their efforts to sign a striker have so far been problematic.Joao Pedro was one of the names on their shortlist after two strong campaigns with Brighton.Isak is looking to explore his options outside of NewcastleGettyHe scored their second goal in the Carabao Cup final win over LiverpoolGettyBut Chelsea beat them to his signing in a £60m move, with the Brazilian scoring three goals in three games at the Club World Cup.Ekitike was another option for Newcastle, but Liverpool beat the Magpies to the punch.He has signed a six-year deal and already joined his new teammates for their pre-season tour in Asia.Howe’s hopes of keeping IsakUncertainty over Isak’s future at Newcastle is nothing new as Arsenal have held long-term interest.Howe left him out of their squad that lost 4-0 to Celtic in a friendly last week amid the speculation over a move to Liverpool.However, he insisted that the club want to keep him this summer.Howe could lose his star player just weeks before the season startsAFP“I’d never give a guarantee about anybody [staying] because I’ve been in football long enough to know I could end up looking silly,” he said.“But, the desire from everybody to keep him is as strong as it could be. Fingers crossed that will happen for us.“We love him as a player and a person and want him to stay, and that is right through the club. “He’s an outstanding talent and a player we cherish. I think for any player speculation’s not an easy thing to deal with and not an easy thing to understand.“When you’re fielding calls and messages from players and people asking you all sorts. “The media now is so strong and the media message goes far and wide. “I don’t think it’s easy for any player to be under that scrutiny and that’s part, ten per cent, of the reason why he wasn’t here today.“I just want him to focus on himself and his training and being ready for next week.”Isak has been excellent for Newcastle since his 2022 move from Real Sociedad